1. Field of the Invention
The present invention relates to a method of and a system for holding a bus during insertion/extraction of an IC card in a computer.
2. Description of the Related Art
In recent years, small, light-weight, and portable lap-top type computers have been used in place of desk-top type computers in the field of personal computers. In a lap-top type personal computer, a flat panel display, a thin type floppy disk drive, an IC (Integrated Circuit) card and the like are utilized as an input/output device.
For example, in a lap-top type personal computer using an IC card as an external memory medium, data stored in the IC card is destructed or a CPU (Central Processing Unit) hangs up at insertion or extraction of the IC card in the computer while the power supply is turned on and the IC card is accessed by the CPU.
The CPU also hangs up at insertion/extraction of the IC card when an input/output device other than an IC card is accessed by the CPU and the input/output device and the IC card are connected directly to a common bus. The reason for this is that in a number of lap-top type personal computers, the input/output devices are directly connected to a bus without using any buffer in order to decrease the number of computer parts for reduction in the size and weight.
Accordingly, it is therefore desirable to provide a computer capable of preventing destruction of data in an IC card and hang-up of the CPU when the IC card is inserted to and extracted from a computer and the power supply is on.